Vehicle-mounted generator and generator optimization method

Abstract

The invention discloses a vehicle-mounted generator and a generator optimization method. The vehicle-mounted generator comprises a casing provided with a rotor and a stator, and windings are arranged on a rotor iron core and a stator iron core; the generator rotor is of a double-shaft-extension structure, one end of the generator rotor is connected with a steam end bearing, the other end of the generator rotor is connected with excitation equipment through an excitation end bearing, a plurality of rotor wire grooves are evenly formed in a rotor core, a ventilation groove is formed in the end, between every two adjacent rotor wire grooves, of the rotor core, and rotor coil ventilation holes in the rotor wire grooves are arranged in a staggered mode. According to the invention, the ventilation and heat dissipation capability of the rotor can be effectively improved, the axial length of the whole machine is greatly shortened, and the amount of ferromagnetic materials, the overall weight and the size of the generator are reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to a mobile power generation equipment, in particular to a vehicle-mounted generator and a generator optimization method. BACKGROUND

[0002] With the continuous development of shale gas exploitation technology worldwide, the power requirement of on-site electricity is high, and the demand for high-power mobile vehicle-mounted power generation equipment is increasing. However, the traditional 35MW vehicle-mounted generator weighs up to 60 tons, the axial length is more than 3.5 meters, and the heat dissipation relies on an external oil cooling system (occupying 30% of the space). When the rotor temperature rise limit is ≤70K, a ventilation channel 57X5.5mm is needed, resulting in a core length of 2200mm, which is difficult to meet the mobile deployment requirements of shale exploitation sites. Moreover, the existing products also require a large number of auxiliary equipment such as lubricating oil stations, and the power station deployment and transposition period is long, which is difficult to meet the demand for vehicle-mounted mobile power generation equipment. SUMMARY

[0003] The purpose of the present application is to provide a vehicle-mounted generator and a generator optimization method, which can effectively improve the rotor ventilation and heat dissipation capacity, further greatly shorten the axial length of the whole machine, reduce the amount of ferromagnetic material, the overall weight and volume of the generator.

[0004] The present application adopts the following technical solutions: A vehicle-mounted generator, comprising a machine shell provided with a rotor and a stator, a rotor core and a stator core, and windings arranged on the rotor core and the stator core; the generator rotor is a single shaft extension structure, and the two ends of the generator rotor are rotatably connected with the machine shell; one end of the generator rotor is connected with a gas turbine, and the other end is provided with an excitation system; a plurality of rotor slot grooves are uniformly arranged on the rotor body, a first ventilation groove is arranged on the rotor body between the adjacent two rotor slot grooves, and the rotor coil ventilation holes in the rotor slot groove are staggered.

[0005] The lower part of the rotor coil and the bottom of the rotor slot groove form a second ventilation groove.

[0006] An integrated high-efficiency high-pressure inner fan of wing type is arranged in the machine shell.

[0007] NOMEX paper is used for the rotor slot groove insulation and the lower insulation of the generator retaining ring.

[0008] The copper wires in the rotor coil and at the end of the rotor slot groove are connected by increasing the copper wire welding method.

[0009] The copper wires in the rotor slot groove and the copper wires at the end of the rotor slot groove are designed with different widths.

[0010] The copper wires at the end of the rotor slot groove are wider than the copper wires in the rotor slot groove.

[0011] A semicircular machine shell is used at the lower end of the middle part of the machine shell.

[0012] The generator excitation end tail is provided with a shaft pump.

[0013] The rotor winding and the stator winding both adopt H-grade insulation level.

[0014] The on-board generator optimization method comprises: (1) the stator axial and radial dimensions are reduced, and the stator air duct and stator slot numbers are reduced; meanwhile, the stator air duct size, stator slot size and the number of conductors in the slot are increased; (2) the rotor outer diameter is synchronously reduced, the rotor winding wire gauge is adjusted and the number of turns of the coil in the rotor slot is reduced, so as to maintain the stability of electromagnetic performance; (3) the stator tooth loss is reduced through magnetic circuit partition optimization, and the stator yoke, rotor tooth and air gap magnetic energy density are improved, so as to match the electromagnetic load after the stator size adjustment.

[0015] The first ventilation groove and the second ventilation groove at the bottom of the rotor slot are specially designed on the rotor body, and the rotor coil ventilation hole is arranged in the misaligned tooth in the rotor slot, so that the rotor ventilation and heat dissipation capacity can be effectively improved. The application also cooperates with the above-mentioned heat dissipation structure, and sets an integrated high-efficiency high-pressure inner fan with a NACA airfoil type at the motor end and the excitation end in the machine shell, so as to further strengthen the heat dissipation effect.

[0016] Further, the rotor winding and the stator winding both adopt H-grade insulation level, have the advantages of long service life and wide application range, also have good moisture-proof and corrosion-resistant performance, and can guarantee the safe and stable operation of the generator. At the same time, the NOMEX paper is further used to strengthen the rotor slot insulation and the insulation effect under the generator guard ring.

[0017] Further, the application also adopts the copper wire welding mode to connect the copper conductors located in the rotor slot and at the end of the rotor slot in the rotor coil, and the copper conductor at the end of the rotor slot is wider than the copper conductor in the rotor slot, so as to effectively increase the heat dissipation area and reduce the rotor temperature rise; and the crack caused by the bending of the copper conductor at the end of the rotor slot can be avoided, so as to reduce the safety hidden danger.

[0018] Further, the application also utilizes stator space reconstruction, rotor collaborative scaling, magnetic circuit partition strengthening and material upgrading adaptation, finally realizes the comprehensive breakthrough of total loss reduction of 6.9% and efficiency improvement of 0.2% under the premise of constant rated power (35MW) and voltage (13.8kV), solves the contradiction problem of lightweight and high efficiency of high-power generator, greatly shortens the overall axial length, reduces the amount of ferromagnetic material, overall weight and volume of the generator, significantly improves the capability of the on-board application scene, and reduces the load of the on-board platform. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1It is a structural schematic view of the generator shell in the application; Figure 2 It is a structural schematic view of the generator shell in the application; Figure 1 It is a structural schematic view of the generator shell in the application; Figure 3 It is a structural schematic view of the wing type integrated inner fan in the application; Figure 4 It is a structural schematic view of the generator shell in the application; Figure 3 It is a structural schematic view of the generator shell in the application; Figure 5 It is a structural schematic view of the rotor core in the application; Figure 6 It is a structural schematic view of the rotor core in the application; Figure 7 It is a structural schematic view of the rotor core in the application; DETAILED DESCRIPTION

[0020] The technical solutions in the embodiments of the application will be clearly and completely described below with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the application.

[0021] As shown in the background, the existing high-power generator has the problems of heavy weight, large volume, poor heat dissipation effect, and the need for a large number of auxiliary equipment such as lubricating oil stations, long deployment and transfer period of power stations, and difficulty in meeting the demand for vehicle-mounted mobile power generation equipment.

[0022] To solve the above technical problems, as shown in Figures 1 to 7 The application provides a vehicle-mounted generator, which comprises a shell 1 provided with a rotor and a stator, and windings are arranged on the rotor core and the stator core; the generator rotor is in a single-shaft extension structure, and the two ends of the generator rotor are rotationally connected with the shell 1 through a gas end bearing 2 and an excitation end bearing; one end of the generator rotor is connected with a gas turbine, and the other end of the generator rotor is provided with an excitation system 3; a plurality of rotor slots 5 are uniformly arranged on the rotor body, a first ventilation groove 6 is arranged on the rotor body between two adjacent rotor slots 5, rotor coil ventilation holes 7 are arranged in a staggered manner in the rotor slots 5, and a second ventilation groove 8 is formed between the lower part of the rotor coil and the bottom of the rotor slot 5.

[0023] As shown in Figure 5 and Figure 6 The above rotor heat dissipation structure effectively improves the rotor ventilation and heat dissipation capacity. The rotor coil ventilation holes 7 arranged in a staggered manner can make the airflow produce turbulent disturbance, and the heat transfer coefficient is increased by 18% compared with parallel holes; the second ventilation groove 8 and the first ventilation groove 6 form a double-path air pressure gradient, and the wind speed is increased by 22%.

[0024] To match the rotor heat dissipation structure described above, as shown in Figure 3 and Figure 4 , the present application is provided with NACA airfoil integral high-efficiency high-pressure inner fan 9 at the steam end and the excitation end in the casing 1, which replaces the traditional fan by the fan with streamlined impeller, and further improves the motor ventilation and heat dissipation capacity, and reduces the rotor temperature rise by combining the rotor heat dissipation structure described above.

[0025] In the present application, the rotor slot 5 insulation and the generator guard ring insulation are both made of insulation materials with good insulation effect and better heat dissipation, such as NOMEX paper, compared with the existing generator, the present application can make the insulation thinner, which is helpful for copper wire heat dissipation and improves the overall heat resistance of the motor. In the present application, the rotor winding and the stator winding are both made of H-grade insulation, which has the advantages of long service life, wide application range, good moisture resistance and corrosion resistance, and can ensure the safe and stable operation of the generator.

[0026] In the present application, as shown in Figure 7 , the copper wires in the rotor coil located in the rotor slot 5 and at the end of the rotor slot 5 are connected by increasing the copper wire welding method, the straight part of the copper wire 10 in the rotor slot 5 and the copper wire 11 at the end of the rotor slot 5 are designed with unequal width, and the copper wire 11 at the end of the rotor slot 5 is wider than the copper wire 10 in the rotor slot 5; the above design can effectively increase the heat dissipation area and reduce the rotor temperature rise; and can avoid the cracks caused by bending of the copper wire at the end of the rotor slot 5, thereby reducing the safety hazard.

[0027] Different from the rectangular cuboid shape of the traditional box-type motor, the lower end 4 of the middle part of the casing 1 in the present application adopts a semicircular casing, which can reduce the internal wind resistance of the generator, speed up the heat dissipation speed, increase the external operation space of the generator on the vehicle platform, and also can increase the space utilization rate of the generator and improve the overall strength and stiffness of the casing 1. Compared with the existing rectangular steel plate type welded casing 1, the material is more saved, the weight is lighter, and the transfer capacity of the vehicle platform can be improved.

[0028] Due to the need for lubricating oil station and other auxiliary equipment in the existing generator technology, in order to overcome the above inconvenience, a shaft pump is provided at the tail of the excitation end of the generator in the present application to ensure the lubricating oil supply of the bearing during operation, which simplifies the oil station structure and meets the requirements of on-site rapid station power generation.

[0029] The present application reduces the weight of the traditional box-type motor under the same power from 60t to below 35t, and the volume is reduced by more than 50.2%. The present application can increase the external operation space of the motor on the vehicle platform, adapt to the demand of high-power mobile vehicle power generation, and has high market application prospect.

[0030] To adapt to the demand of vehicle mobile power generation equipment, the size of the generator needs to be reduced, but the size reduction of the generator will directly affect the motor power and heat dissipation effect, in order to solve the above problems, based on the structure of the optimized generator, the application further provides a vehicle-mounted generator optimization method, comprising: (1) reduce the axial and radial size of the stator, and reduce the number of stator air ducts and stator slots; while increasing the size of the stator air duct, the size of the stator slot and the number of conductors in the slot, so as to adapt to the demand of vehicle mobile power generation equipment, realize lightweight and high power density compatibility; In the application, the stator layout can be first compacted, that is, the axial and radial lengths of the stator are reduced, such as reducing the length of the stator core , and reducing the outer diameter of the stator , and reducing the inner diameter of the stator , so as to realize the axial space compression and radial compact topology of the stator, and reduce the material consumption; Since the size of the stator is small, the number of stator air ducts and stator slots is also reduced in the application, such as reducing the number of stator air ducts , and reducing the number of stator slots ; In the embodiment, 26 is greater than or equal to 20, 10 is greater than or equal to 4, 13 is greater than or equal to 7, 50 is greater than or equal to 44, and 33 is greater than or equal to 27; Since the axial and radial lengths of the stator are reduced, in order to ensure that the motor power and heat dissipation effect are not affected after the size is reduced, the size of the stator air duct, the size of the stator slot and the number of conductors in the slot are also optimized in the application: In the application, in order to adapt to the change of the size of the stator, the width of the stator air duct can be increased , the area of the stator slot can be increased , and the number of conductors in the slot can be increased ; The increase of the width of the stator air duct can ensure that the stator heat dissipation efficiency does not decrease after the size of the stator and the number of stator air ducts are reduced, so as to ensure the stable operation of the generator; the increase of the size of the stator slot and the number of conductors in the slot can improve the space utilization rate of the stator slot through the design idea of "large slot type + high conductor filling rate"; In the embodiment, 12 is greater than or equal to 6, 19 is greater than or equal to 12, and 110 is greater than or equal to 90; By the above optimization method, the application can reconstruct the stator space by axial / radial bidirectional compression, offset the influence of the reduction of the number of stator slots by slot expansion and conductor densification, realize the compatibility of lightweight and high power density, and effectively reduce the material usage (such as reducing the stator copper weight).

[0031] (2) The outer diameter of the rotor is reduced synchronously, the wire gauge of the rotor winding is adjusted, and the number of turns of the coil in the rotor slot is reduced to maintain the stability of electromagnetic performance. In the application, to adapt to the change of the size of the stator, the length of the outer diameter of the rotor is shortened in proportion to the reduction of the inner diameter of the stator to maintain a reasonable air gap size. In the embodiment, 13≥ 7. To adapt to the change of the length of the outer diameter of the rotor, the electromagnetic parameters of the rotor are adjusted in the application to maintain the stability of electromagnetic performance through fine adjustment of the number of turns.

[0032] Specifically, compared with the existing conventional 35MW generator, in the embodiment, the number of rotor slots can be maintained as 24 slots unchanged, the wire gauge of the rotor winding is increased, such as being fine-tuned from 5.7X30.36mm to 5.8X30.36mm, and the number of turns of the coil in the rotor slot is reduced, wherein the number of turns of the coil in the No.1 rotor slot can be reduced from 13 turns to 12 turns, and the number of turns of the coil in the other rotor slots is reduced from 16 turns to 14 turns, so that the volume is reduced while the ampere-turn distribution is optimized, and the rotor copper weight is reduced.

[0033] (3) The tooth loss of the stator is reduced through magnetic circuit partition optimization, and the magnetic energy density of the stator yoke, the rotor tooth and the air gap is increased to match the electromagnetic load after the stator is shortened. In the application, the magnetic energy density of the stator tooth can be reduced , the magnetic energy density of the stator yoke is increased , the magnetic energy density of the air gap is increased , the magnetic energy density of the rotor tooth is increased , and finally a new magnetic circuit design of “low stator tooth saturation + high rotor and air gap magnetic density” is formed, so that the electromagnetic load demand after the stator is shortened is adapted. In the embodiment, the silicon steel sheet material can be further upgraded, and the silicon steel sheet with high magnetic induction and low iron loss is used to replace the conventional silicon steel sheet, such as using silicon steel sheet 50W290 to replace silicon steel sheet 50W400, so as to support the new magnetic circuit design after the magnetic density reconstruction.

[0034] In the embodiment, 17≥ 10, 4≥ 1, 10≥ 4, 21≥ 15.

[0035] In this embodiment, the motor design scheme optimized by the vehicle-mounted generator optimization method according to the application is shown in the following table: Through the above optimization means, the vehicle-mounted generator optimization method according to the application can realize material and manufacturing collaborative upgrading compared with the existing conventional 35MW generator, that is: 1. Cooling structure optimization: the number of stator air ducts is reduced but the width is increased, which is suitable for shortening the iron core and ensuring the heat dissipation capacity; 2. Conductive material optimization: the copper weight of the stator and rotor is reduced by 35.6% and 19.1% respectively, which reflects the high conductivity utilization rate design; 3. Permeable material optimization: 50W290 high-end silicon steel sheets are used, and the iron loss is reduced by 27.5% (nominal value) compared with 50W400; 4. Copper consumption optimization: the basic copper consumption of the stator is slightly increased (98.8kW→103kW), but the rotor copper consumption is significantly reduced (124.83kW→105kW, reduced by 15.9%), and the total copper consumption is reduced; 5. Iron loss and stray loss optimization: the iron loss is slightly increased (79.73kW→83kW) due to the redistribution of magnetic density, but the additional loss is reduced from 172kW to 130kW (24.4%), and the bearing loss is reduced from 52kW to 42kW (19.2%).

[0036] 6. Total loss optimization: from 677kW to 630kW (6.9% reduction), and the support efficiency is increased from 98.1% to 98.3%.

[0037] The vehicle-mounted generator optimization method according to the application takes the rotor copper consumption and additional loss as the breakthrough point, realizes energy efficiency leap through electromagnetic optimization and structure simplification, realizes material weight reduction through stator space reconstruction (iron core shortening + slot type expansion), realizes copper consumption reduction through rotor collaborative scaling (outer diameter reduction + turn optimization), realizes iron loss control through magnetic circuit partition strengthening (low stator tooth saturation + high rotor magnetic density), realizes high frequency loss suppression through material upgrade adaptation (50W290 silicon steel sheet), and finally realizes total loss reduction of 6.9% and efficiency improvement of 0.2% compared with the existing conventional 35MW generator under the premise of constant rated power (35MW) and voltage (13.8kV), solves the contradiction problem of lightweight and high efficiency of high-power generator, greatly shortens the axial length of the whole machine, reduces the amount of ferromagnetic material, the overall weight and volume of the generator, significantly improves the capability of the vehicle-mounted application scene, and reduces the load of the vehicle-mounted platform.

[0038] Finally, it should be noted that the above only describes the preferred embodiments of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art will appreciate that the technical solutions described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalent features, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A vehicle-mounted generator, comprising a housing having a rotor and a stator, with windings disposed on both the rotor core and the stator core; a single-shaft-extended generator rotor having two ends rotatably connected to the housing; one end of the generator rotor being connected to a gas turbine, and the other end being provided with an excitation system; a plurality of rotor slots being evenly distributed on the rotor body, a first ventilation slot being provided on the rotor body between two adjacent rotor slots, and rotor coil ventilation holes within the rotor slots being staggered.

2. The vehicle-mounted generator according to claim 1, characterized in that: The lower part of the rotor coil and the bottom of the rotor slot form a second ventilation slot.

3. The vehicle-mounted generator according to claim 1, characterized in that: An wing-shaped integrated internal fan is arranged in the casing.

4. The vehicle-mounted generator according to claim 1, characterized in that: The rotor slot insulation and the lower insulation of the generator guard ring are both made of NOMEX paper.

5. The vehicle-mounted generator according to claim 1, characterized in that: The copper wires in the rotor coil located in the rotor slot and at the ends of the rotor slot are connected by adding copper wire welding.

6. The vehicle-mounted generator according to claim 5, characterized in that: The copper wires in the rotor slots and the copper wires at the ends of the rotor slots are designed with unequal widths.

7. The vehicle-mounted generator according to claim 6, characterized in that: The copper wire at the end of the rotor slot is wider than the copper wire inside the rotor slot.

8. The vehicle-mounted generator according to claim 1, characterized in that: The lower middle end of the casing adopts a semicircular casing.

9. The vehicle-mounted generator according to claim 1, characterized in that: Both the rotor winding and the stator winding adopt H-class insulation grade.

10. A method for optimizing a vehicle-mounted generator according to any one of claims 1 to 9, comprising: (1) Reduce the axial and radial dimensions of the stator, and reduce the number of stator air ducts and stator slots; at the same time, increase the size of the stator air duct, the size of the stator slots, and the number of conductors in the slots; (2) Simultaneously reduce the rotor outer diameter, adjust the rotor winding wire gauge and reduce the number of coil turns in the rotor slot to maintain the stability of electromagnetic performance; (3) By optimizing the magnetic circuit partitioning, the stator tooth loss is reduced, and at the same time, the magnetic energy density of the stator yoke, rotor teeth and air gap is increased to match the electromagnetic load after the stator size is adjusted.

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